3ce3a5a952
When monitors changed, previous monitor instances are defunct, and any reference holder should drop its reference. Sometimes they will want to continue having a reference to the same monitor, so add this function to make it possible to find it. Currently the output and crtc references are invalid, as they are not yet reference counted, so this can only look at cached fields. https://bugzilla.gnome.org/show_bug.cgi?id=784199